alternativeClasses.java

// From Fixing Object oriented abusers, Manh Phan https://ducmanhphan.github.io/2020-01-24-Fixing-object-oriented-abusers/
 
public class CheckoutHandlder {
     // ...
     public double convertToCurrency(double price, String currencyTo) {
         if (currencyTo.equalsIgnoreCase("EUR")) {
             return price * 0.9;
         } else if (currencyTo.equalsIgnoreCase("CAD")) {
             return price * 1.35;
         } else {
             throw new IllegalArgumentException("Unrecognized currency: " + currencyTo);
         }
     }
 }

 public class SimpleCurrencyConverter {
     private String currencyTo;

     public SimpleCurrencyConverter(String currencyTo) {
         this.currencyTo = currencyTo;
     }

     public double convert(double price) {
         if (currencyTo.equalsIgnoreCase("EUR")) {
             return price * 0.9;
         } else if (currencyTo.equalsIgnoreCase("CAD")) {
             return price * 1.35;
         } else {
             throw new IllegalArgumentException("Unrecognized currency: " + currencyTo);
         }
     }
 }